improve example test by sorting output (cadence-workflow#1366)

* improve example test by sorting output

* replace slices pkg with sort

* address comments

Author: ketsiambaku

internal/common/debug/example_test.go

@@ -23,6 +23,8 @@ package debug
 import (
 	"encoding/json"
 	"fmt"
+	"sort"
+	"strings"
 	"sync"
 
 	"go.uber.org/atomic"
@@ -75,6 +77,9 @@ func (ati *activityTrackerImpl) Stats() Activities {
 			}{Info: a, Count: count})
 		}
 	}
+	sort.Slice(activities, func(i, j int) bool {
+		return strings.Compare(activities[i].Info.ActivityType, activities[j].Info.ActivityType) < 0
+	})
 	return activities
 }